The Mountain Engines have been developed slightly throughout the Extended Railway Series, using events
from the Snowdon Mountain Railway. It has also allowed for lesser known characters such as Ernest, Wilfred, Eric, Alaric and
Shane Dooiney to be featured following their missing out on the first book by the Rev. Awdry in the 1960s. The steam fleet
remains unchanged from the old days.

The first batch of five locomotives were built for the Culdee Fell Railway in 1900 at Winterthur in
Switzerland, and work on the Abt rack system, pinion wheels below the engine engaging with a fixed ‘rack’ of teeth
set between the rails.

The names bestowed upon the first five appear to have some historical significance associated
with the railway or indeed with Sudrian affairs and folklore. No.1 Godred was named after King Godred Crovan, ruler of Sodor
& Man between 1079 and 1095, hailed in folklore as a hero; No.4, Culdee, and No.5, Shane Dooiney are named after the two
tallest Sodor Mountains – the names of No.2, Ernest and No.3, Wilfred, remain obscured from historical records. All
five were delivered in time for the inspection of the railway prior to opening in that year, where Culdee was put through
his paces by the Inspector.

However, tragedy struck following a successful first month of operation when Godred ran
away on the descending run from the summit, left the rails and plummeted down the mountainside. The damage to the locomotive
was extensive, and he was immediately withdrawn from service. Although the locomotive’s salvageable components were,
for many years, used for spares for the serviceable locomotives, the management have never replaced him as the locomotive
No.1, whether this has been out of superstition, respect or historical significance remains unknown.

Nos. 2 to 5 carried
on diligently for sixty years before the railway’s management decided to renew and revitalise the fleet in the mid 1960s.
All four locomotives were returned individually to Winterthur for overhaul, with a set of newly built locomotives arriving
in their place. No.6 was named Lord Harry, after Lord Harry Barrane, the Chairman and Owner of the Mountain Railway at the
time. No.7 received the name Alaric, and No.8, Eric.

No.6 proved extremely temperamental in its early days, and after
a very notable incident where the locomotive derailed at the Summit station, blocking all paths in and out, the name Lord
Harry was removed both as punishment to the engine, and out of respect for the owner. No.6 was then placed onto goods duty
for several weeks before being used in the daring and dangerous rescue of climbers stranded on Devil’s Back. He was
renamed in the honour of one of these men, Patrick, and retains the name to this day.

The first batch of locomotives are based on those built
for the Snowdon Mountain Railway in 1896, with the second batch delivered to Sodor in the 1960s, based on the new super-heated
versions which arrived in the 1920s. By comparison, the Culdee Fell 7 and 8 remain in active service, as opposed to their
counterparts who were withdrawn in the late 80s and early 90s, for failing to remain 'steam-tight'. The future of these locomotives
remains uncertain, but it is unlikely they will ever see service again.

Norman and Betty were brought to the railway in 1995 to reduce costs and maximise efficiency. Betty
has always been a gentle, friendly and occasionally anxious engine, whilst Norman has always been full of his own self importance
and arrogance, but was soon brought back down to earth following the trickery of Vermat the Rail Car when he tried to avoid
being sent back to the manufacturers following multiple faults. Norman has learnt humility since and become a far better engine
as a result, but still retains his snooty characteristics.

Whilst not universally embraced as a ‘replacement’ to steam, the benefits of Dieselisation
had been felt across the Island of Sodor in terms of economy and ease. The majority of the railway companies on the island
boasted at least one, with the exception of the Culdee Fell Mountain Railway, which had become the last bastion of full-steam
service. For a number of years, the company traded off this ‘other’ unique distinction, but by the early 1990s,
the attitudes among the railway’s management began to change. They were optimistic that Diesel traction could be beneficial
in carrying out necessary maintenance, engineering work and running other non-revenue earning services up the mountain, such
as ‘The Truck’.

An approach was made to the Snowdon Mountain Railway to borrow one of their Diesel units
in 1991, but given the importance and reliance upon the two existing units of the time, the request was denied. Instead, an
offer to engage in participant observation of the Diesel units was made, and accepted by the Culdee Fell management. Experienced
loco crews were sent across to Llanberis in North Wales on a three week ‘fact-finding’ mission, where they observed
the running, maintenance and costs of the Diesel units. They returned suitably impressed with what they had experienced in
terms of ‘turn-around time’, costs and running, and thoroughly recommended the investment in Diesel motive power
for the purposes the railway was seeking them out for.

Following further consultations with the Snowdon Mountain Railway,
the Culdee Fell management placed an order with Hunslet of Leeds with engines manufactured by Rolls Royce in late 1992. The
locomotives were based on the designs to which the Snowdon Diesel locomotives were built, however, certain technical improvements
were implemented, both to aid performance on the longer Culdee Fell route and to iron out teething problems encountered with
the Snowdon Diesels. In addition to these locomotives, the railway was approached by HPE Tredegar Ltd, who were contracted
to build Diesel Electric Railcars for the Snowdon Mountain Railway. The railway were reluctant to purchase further motive
power at that time, and so agreed to a two-year trial of the Railcar design, beginning in 1996, shortly after the successful
trials of the two Diesel units.

Trials on the two new Diesel locomotives took place in 1995, and they entered service
on the railway in the spring of 1996. Whilst there proved to be some difficulties concerning the hydraulics with No.9, Norman,
No.10, Betty proved to be a more reliable runner and took up responsibility for the non-revenue earning services throughout
her first year in service.

Norman and Betty are based on the Snowdon Mountain Railway’s
Ninian (No.9) and Yeti (No.10) built in 1986. Dieselisation was seen as a necessity on the Mountain line, given the cost involved
of running the railway with steam locomotives. Since then, Diesels have proven to be the preferred choice of crews and management
from a costing and cleanliness point of view, however, steam locomotion still remains a popular and lasting feature of the
railway when trying to vie for tourist traffic.